1. Field of the Invention
The present invention relates to a method and system for the operational testing of a device for the balancing of bodies of rotation, and more specifically to a method and system for the operational testing of a device for the balancing of a rotor (in particular, automobile wheels) in two balancing planes.
2. Description of the Prior Art
Devices for the balancing of out-of-balance rotor bodies are known in the art, and have varying designs.
For example, German Pat. No. 27 32 738 discloses such a device for the balancing of a rotor in two balancing planes. As the rotational body is rotated, forces are applied to pickup devices provided in the device, and the pickup devices translate the applied forces to corresponding dimensions in the plane of the rotating body.
A second device or apparatus for balancing rotors is disclosed in U.S. Pat. No. 4,162,634, assigned to the assignee of the present invention. The latter patent discloses a method and apparatus for balancing a rotor in at least one plane, geometrical parameters of the rotor being stored along with test values representing the rotor in balance as determined during a test run. The stored values are transmitted to a computer which determines the size and phase relationship of counterweights necessary to balance the rotor. Both dynamic and static unbalance are displayed on appropriate indicators of the device.
A further wheel balancing apparatus is disclosed in U.S. Pat. No. 4,046,017. Of particular interest is the fact that, as stated in the patent, wheels to be balanced may vary in diameter and in width, and the positions of the inner and outer rims of the wheel may vary in offset distance from the bearing housing. Accordingly, the apparatus of the latter U.S. patent is provided with dials for providing the computing unit with the following wheel-related parameters: the diameter (or radius) of the inner and outer wheel rims; the width of the wheel (that is, the distance between the inner wheel plane and the outer wheel plane); and the offset distance from a force transducer or pickup device to the inner wheel rim.
In devices of the kind discussed above, the rotor or wheel is typically mounted on a clamping fixture or shaft, the clamping fixture being braced directly, or by means of measuring value loggers, in relation to the housing of the device. In addition, such devices are provided with unbalance-measuring devices for determining the magnitude and direction of unbalance.
For the purpose of adjusting or calibrating such balancing devices, typical prior art techniques call for a completely balanced rotor to be fixed to the clamping fixture, and an artificial unbalance is generated by the addition of a known weight to the rotor. The unbalance supplied is then measured in a test run by means of an unbalance-measuring device, the magnitude and phase relationship being measured, and indicating instructions being employed for manual adjustment of the balancing machine.
In such prior art arrangements, prior to the actual measuring test run, the computing unit must be mutually adjusted so as to provide it with the geometric dimensions of the rotor. In that regard, the typical technique calls for scanning of the rotor, either manually or automatically, to find the values of the geometric dimensions of the rotor to be employed in the test run. The values thus determined are provided to the computing device. Such a scanning and adjusting process requires considerable time, and may in fact be the source of faulty adjustments (due to human error, and the like). In addition, such a technique of the prior art requires that a completely balanced rotor be available. Moreover, the arrangement and manipulation of such a completely balanced rotor is complicated and time-consuming.